The notion of “a single particle” turns out to be problematic. The thing that requires arbitrarily much information is the amplitude for a particle to be in some particular state.
I should emphasize that amplitudes aren’t just a creature of our models—they are the thing that interfere to give you an diffraction pattern, or the shapes of an electron orbital cloud, or that get manipulated in a quantum computation.
The notion of “a single particle” turns out to be problematic. The thing that requires arbitrarily much information is the amplitude for a particle to be in some particular state.
I should emphasize that amplitudes aren’t just a creature of our models—they are the thing that interfere to give you an diffraction pattern, or the shapes of an electron orbital cloud, or that get manipulated in a quantum computation.